The Sparkle Dun in size #16 imitates a mayfly dun with a trailing shuck of sparkle material, matching freshly hatched insects.
The trailing shuck is the key trigger. Dead-drift it during mayfly hatches, especially to selective risers.
Present it with a drag-free drift, mending your line as needed to extend the drift through the feeding lane. It also makes a highly visible top fly in a dry-dropper rig, pulling double duty as strike indicator.
